res_rtp_asterisk: Fix crash when RTCP is not available during SSRC change

In r400089, a patch was put in to correct erroneous RTCP statistic resets.
Unfortunately, ast_rtp_read can be called on an RTP instance that does not
have RTCP information. This patch prevents that crash by only resetting
the statistics if we do actually have an RTCP instance.

(issue AST-1174)

(closes issue ASTERISK-22667)
Reported by: John Bigelow
........

Merged revisions 401445 from http://svn.asterisk.org/svn/asterisk/branches/1.8

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@401446 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/res/res_rtp_asterisk.c b/res/res_rtp_asterisk.c
index 480877ac22c4b6d4e0b34bc45b4d0e12f82ed496..0af845a68d2fd9563a9330a5856f991c8efb7bb3 100644 (file)
--- a/res/res_rtp_asterisk.c
+++ b/res/res_rtp_asterisk.c
@@ -3664,10 +3664,12 @@ static struct ast_frame *ast_rtp_read(struct ast_rtp_instance *instance, int rtc
                rtp->rxcount = 0;
                rtp->cycles = 0;
                rtp->lastrxseqno = 0;
-               rtp->rtcp->expected_prior = 0;
-               rtp->rtcp->received_prior = 0;
                rtp->last_seqno = 0;
                rtp->last_end_timestamp = 0;
+               if (rtp->rtcp) {
+                       rtp->rtcp->expected_prior = 0;
+                       rtp->rtcp->received_prior = 0;
+               }
        }
 
        rtp->rxssrc = ssrc;